A TRANSITION REGION EXPLOSIVE EVENT OBSERVED IN He II WITH THE MOSES SOUNDING ROCKET

作者：Fox J Lewis^*; Kankelborg Charles C; Thomas Roger J

来源：Astrophysical Journal, 2010, 719(2): 1132-1143.

DOI：10.1088/0004-637X/719/2/1132

• instrumentation: spectrographs
• space vehicles: instruments
• Sun: transition region
• Sun: UV radiation
• techniques: imaging spectroscopy

Transition region explosive events (EEs) have been observed with slit spectrographs since at least 1975, most commonly in lines of C IV (1548 angstrom, 1550 angstrom) and Si IV (1393 angstrom, 1402 angstrom). We report what we believe to be the first observation of a transition region EE in He II 304 angstrom. With the Multi-Order Solar EUV Spectrograph (MOSES) sounding rocket, a novel slitless imaging spectrograph, we are able to see the spatial structure of the event. We observe a bright core expelling two jets that are distinctly non-collinear, in directions that are not anti-parallel. The jets have sky-plane velocities of order 75 km s(-1) and line-of-sight velocities of +75 km s(-1) (blue) and -30 km s(-1) (red). The core is a region of high non-thermal Doppler broadening, characteristic of EEs, with maximal broadening 380 km s(-1) FWHM. It is possible to resolve the core broadening into red and blue line-of-sight components of maximum Doppler velocities +160 km s(-1) and -220 km s(-1). The event lasts more than 150 s. Its properties correspond to the larger, long-lived, and more energetic EEs observed in other wavelengths.

• 出版日期2010-8-20